A B757 received an EGPWS warning at 3;100 FT approaching KELSO waypoint from EMIVO waypoint on the MDPP RNAV Runway 8 approach.

Narrative

We were flying the RNAV (GNSS) Runway 8 approach to a visual. First Officer was flying approaching KESLO waypoint; on vertical path on LNAV track. We broke out shortly after passing 4;000 FT or so; just before the turn to KESLO from EMIVO. As we approached KESLO; I remember commenting on the ridge ahead and that it would be interesting to see what the radio altimeter reading reduces to. On track; on vertical path the whole time at 3;100 FT MSL and 1;440 FT Radio Altitude. After a rapid RA movement of at least 1;000 FT; we got a 'Terrain; Terrain; Pull Up; Pull Up' warning. Since First Officer and I were already highly aware of the terrain and we were looking at it as well as the runway; we continued. You may note that the FAF on this particular approach is almost 10 NM from the runway end; so we were not fully configured for landing in this fully VMC situation. We were at about 170 KTS at the time with 20 flaps. I am not convinced that had we been at approach speed; some 35 KTS less; that we would not have gotten this warning. I think that in IMC conditions; the obvious go-around will be the result in the future on this approach that is certainly what we would have found if we had not had everything in sight. As a crew we think that a change in the definition of this final approach fix would be appropriate.